Intracellular calcium handling pathways in smooth and skeletal muscle (ECC) (ECC)

Intracellular calcium (Ca2+) handling pathways in smooth and skeletal muscle are complex systems responsible for regulating the concentration of cytosolic calcium to facilitate muscle contraction and relaxation. In skeletal muscle, the process is initiated by excitation-contraction coupling, where the dihydropyridine receptor (DHPR) senses membrane depolarization and triggers Ca2+ release from the sarcoplasmic reticulum (SR) through the ryanodine receptor 1 (RyR1) (StatPearls, 2023). Smooth muscle calcium handling involves both extracellular Ca2+ influx via voltage-gated channels and intracellular release mediated by inositol trisphosphate (IP3) receptors (NCBI, 2021). Proper functioning of these pathways is critical, as dysregulation can lead to life-threatening conditions such as malignant hyperthermia or chronic muscle weakness (PubMed, 2022). Pharmacological agents like dantrolene target these pathways by inhibiting RyR1 to treat hypermetabolic crises, while calcium channel blockers are used to manage smooth muscle tone in cardiovascular diseases (PubChem, 2024). The sarcoplasmic/endoplasmic reticulum calcium ATPase (SERCA) pump also plays a vital role by sequestering Ca2+ back into the SR to allow for muscle relaxation. Understanding these pathways is vital for developing therapies for genetic myopathies and vascular disorders.

Other names

Excitation-contraction couplingCalcium signalingSarcoplasmic reticulum calcium cyclingCalcium homeostasis

Modulation of calcium release from the sarcoplasmic reticulum via ryanodine receptors, inhibition of L-type voltage-gated calcium channels, or inhibition of the sarcoplasmic/endoplasmic reticulum calcium ATPase (SERCA) pump.